Circuit breaker



Patented May l11, 1926.t

tJ'ru'rrEDy STATES- .PATENT oFFlcE,

WILLIAM ANSELM COATEs, F erroELTON-CUMHARDY, AND 'GEORGE y:snowman GITTINS AND DAVID REGINALD DAVIns, or sTRE'rFoRD, MANCHESTER, ENGLAND,

ASSIGNORS TO WESTINGHOUSE ELECT CORPORATION 0F PENNSYLVANIA.

RIC kAND MANUFACTURING COMPANY, "A

CIRCUIT BREAKER.

Application filed June 5, 1922. Serial No. 566,032.

Our invention relates to electric switches and particularly to means for supporting the fixed contact members of such switches and conducting the current thereto.

A A very usual construction of oil-immersed switches comprises two fixed contact members connected by means of a movable bridge piece, the lixed contact members being supported on two parallel rods or studs mounted on and dependin from the cover or top casting of the switc through which rods or studs the current is conducted to said contact members. In the case of switches which are employed to carry very heavy currents, the magnetic repulsive force between the two rods or studs vmay be so large, when the current is flowing, as to cause a displacement of the contact members atthe ends of said rods, particularly where the rods are ot a considerable length, and this displacement may interfere with the correct operation "of the switch.

Our invention has for its objects the provision of means for preventing the distortion of a pair of parallel conductors under magnetic stresses and the provision of an improved form of ,switch apparatusm According toy they present invention,kthe

conductors supporting the A`fixed Contact members vare, made concentric, one of the?- conductors being tubular` andenclosing of a rod, suitable insulation being provided between the two conductors. -The'ixed contact memb-ers'may be mounted on the ends vof the rodand tube, respectively., in` any suitable manner,v ,and are positioned for. engagement by the movable bridging member of the switch. 't

The single" figure of thedrawing is a view, partially in section ,and partially in side elevation, of a switchfembodyinglour invention. if A The switch shown comprises anoihtank 1 and a switch head orcastingfofjusnal construction, two stationary ,contactf` meinbers 3 and y4` and .two lmovable ``britlk, ,1,`fing members 5 which, as shown,l are .prefei'kably of the brush type comprising a bundle'of laminated conductinglstrips Glfelampedibetween supporting members/ l fandx815flby screws 9, the said bridging.''members` 5'being moved by means of aswitch-operating Mot' the latter.

theinpivotal connectioii" u'p rod 10 through mechanism which will be hereinafter described in detail.

The stationary contact members 8 and 4, are, respectively, connected with and supported by a tubular conductor 11 and a rod conductor 12 concentrically disposed within the tubular conductor 11. The contact members 3 `and 4 lmay be connected to the conductors 11 and 12 by any well known means, such as by screw threaded engagement, as illustrated. The inner rod conductor 12 isinsulated from the tubular conductor 11 by means of a tube 13 of insulating material which is preferably continued beyond the ends of the tubular conductor 11 to the lower contact member 4 at one end and to a terminal block 14 clamped to the .upper end of the rod 12. A tube 15 of insulating material covers the tubular conductor j 11 and extends between the contact member 3 and a terminal member 16 clamped tothe upper end lof the conductor 11. The concentric insulated conductors'll and 12 pass through' a1 vperforationv :17,1 in the switch head 2 and are supportedion the latter by means of a 'flanged bush;` mem- -ber 18.l ,I 1.v ,:ffuf

The stationary contact membersqfha'ndgjln may be of equal lateral f,widtlif:but, ,preferably,.- the upper v contact;memberg5 isA of l y greater width than.tli,e-.lo,wer. contactzmemwithinfitthe other; .conductor in the form ber 4, the contactacesof bothi/.c'ontactsV- bef ing-at a small `angle,,toythea s.of,.th eeon ductors 11 and 12.insteadje argille-l therewith.` With tliisarifangement bridging .members ,5,Whe11. Qlvsed, 1L aOGCuPyf tions. slightly linclined diro,v t

shown. The `bridges actA symmetrically on :Strainsapportiig"'bikts 8', Afr 'the-tru, are ,Pfvotelly resented upon met@ which are themselvesp edy feloiv 141-00 erl 'contact memb prises two parlais" Suni01ene-memb ;Rotativemovementjo ojcgtio f @ris @about einer peaje@- tion 20 in an upward direction, to bring the brush members 6 simultaneously into engagement with the fixed contact members l3 and 4, is effected by means of a bell-crank lever 20a which is pivotally connected at a point intermediate its ends to the tail portion 2l of one of the members 19. One arm of the lever 20a is pivotally connected to the switch-operating rod 10 which, as will be well understood, may be moved in a substantially vertical direction by hand operation or by electrical or power means. The other arm ot' the lever 20a is pivotally connected in the axial line of the switch conductors 11 and l2 to a link 22 which is of a length substantially equal to that of the shorter arm of the lever 20a and is pivotally supported upon the tail portion 2l of one of the members 19, the link 22 and the arm of the lever 20a connected to it constituting a form of toggle joint. Normally, when the switch is opened, the members 19 fall so that their upper ends rotate outwardlv and the brushes occupy the position shown 1n dotted lines. The tail portions 21 of the members 19 approach one another and the switch operating rod l() falls to the position indicated'in dotted lines so that the point of connection between the link 22 and the lever 20a is raised. Positive separation of the bridging members 5 from the stationar contact members 3 and 4 may be obtained by mechanically depressing the opierating rod 10 which causes the link 22 and lever 20a to turn the members 19 about the extension 20, thereby moving the bridging members 5 to their dotted line posltions.

Circuit breaker apparatus embodying certain features of the above described operating mechanism is disclosed in our co-pending application, Serial No. 566,031, filed June 5, 1922 (Case No. 9925).

It will be understood that, in addition to the main breaks provided between the coutact members 3 and 4 and the bridges 5, shunt or arcing contacts may also be provided of any suitable type.

With the concentric arrangement of the conductors 11 and 12, it will be readily seen that deformation of the conductors by reason of the magnetic field set u by heavy current passing through the switch cannot occur except at the bridge portions 6 of the switch, while the switch operating mechanism may be sufficiently powerful to prevent any appreciable tendency to movement of the bridges away from the contact members 3 and 4.

Various changes in detail and arrangement may be made without departing from the spirit and scope of the invention, as defined in the accompanying claims.

We claim as our invention:

1. In a circuit breaker, two electrical conductors disposed in concentric relation and having insulation interposed therebetween, the inner conductor having its extremity extending beyond the adjacent end of the outer` conductor, and a contact Vmember on each of the said ends arranged concentrically thereof, the peripheral sides of the respective contact members being in parallelism and a bridging member for connecting the contact members.

2. In a circuit breaker, two electrical conductors disposed in concentric relation, the ends of the inner conductor extending beyond the outer conductor and provided with contact members and a movable bridging member for connecting the contact members.

3. In a circuit breaker, two electrical conductors disposed in concentric relation, the ends of the inner conductor extending beyond the outer conductor, two adjacent ends of the conductors being provided with terminal members andl the other two ends thereof being provided with switch contact devices and a bridging member for connect- Y ing the switch contact devices.

4. In an electric switch, the combination with a pair of concentrically arranged conductors provided with longitudinally spaced terminal "members, of oppositely disposed bridging members movable laterally with respect to the said conductors and means for etecting a simultaneous engagement between said bridging members and said terminals.

5. In an electric switch, the combination with a pair of concentrically arranged conductors each provided with a terminal member longitudinally spaced with respect to the other terminal member, of a bridging member for completing a circuit across the said terminals and means for moving the bridging member into and out of engagement 'with the said terminals.

6. In an electric switch, the combination with a pair of concentrically arranged conductor members each provided with a terminal member lying inlongitudinally spaced relation to the other terminal member, the outer terminal being of smaller width than the other terminal, a bridging member pivotally supported at a point beyond the outer terminal, and means for rotatively movin the bridging member into engagement witg the said terminals.

7. In an electric switch comprising two fixed contact members, one disposed vertically above the other, a pair of cooperating bridging members symmetrically arranged on either side of said contact members and pivotally carried upon upwardly projecting arms of a pair of bell-crank levers which are pivoted at a common point beneath the lower Ilixed contact member, the other arms of said bell-crank levers being connected together by a toggle link, and means for operating the said bell-crank levers.

8. An electric switch comprising two eonmembersand mounted for movement in a 10 centric conductors, a fixed Contact member substantially horizontal direction. mounted upon the outer of the two oonduc- In testimony whereof, we have hereunto tors, a. fixed Contact member mounted upon subscribed our names this 18th day of May, the inner of the two conductors and disposed 1922. vertically beneath thepreviously mentioned Contact member and spaced therefrom, and WILLIAM ANSELM COATES. a substantially vertically disposed bridging GEORGE EDWARD GITTINS.

member Cooperating with said fixed Contact DAVID REGINALD DAVIES. 

